Method for reducing Cr in metallurgical slags containing Cr

Abstract

A method for reducing the chromium content from a metallurgical slag, in which the slag is charged onto an iron bath in the liquid state and the reduction of Cr is effected by the iron bath having a C content of 2 to 4% by weight, wherein a) the Cr-containing slag having a Cr content of 2 to 20% by weight is charged onto an iron bath having a C content of below 1% by weight, whereupon b) the carbon content of the iron bath is raised to about 2 to 4% by weight by the addition of carbon carriers at the simultaneous supply of energy, c) the liquid slag having a Cr content of about 0.1% by weight is tapped after the reduction of Cr, d) a cooling agent, preferably scrap, is added to the iron melt and the C content of the melt is lowered to below 1% by weight, and e) a portion of the Cr-containing melt is tapped in the liquid state, while the remaining portion is left in the converter in the liquid state for the treatment of the subsequent melt.

1. A method for reducing the chromium content in a metallurgical slag, in which the slag is charged in a liquid state onto an iron bath in a converter, comprising the steps of:
 a) charging a Cr-containing slag in a liquid state having a Cr content of 2 to 20% by weight onto an iron bath having a C content of below 1% by weight, 
 b) raising the C content of the iron bath to about 2 to 4% by weight by adding carbon carriers and supplying energy, 
 c) tapping the liquid slag, having a Cr content of about 0.1% by weight after reduction of the Cr, 
 d) adding a cooling agent to the iron bath and lowering the C content of the iron bath to below 1% by weight, and 
 e) tapping a portion of the Cr-containing slag in the liquid state, leaving a remaining portion of the Cr-containing slag in the liquid state in the converter for treatment of a subsequent melt. 
 
     
     
       2. A method according to  claim 1 , wherein, in step (d), the C content of the iron bath is lowered to below 0.5% by weight.